Wednesday, November 30th 2022
AMD RDNA3 Second-largest Navi 32 and Third-largest Navi 33 Shader Counts Leaked
The unified shader (stream processor) counts of AMD's upcoming second- and third-largest GPUs based on the RDNA3 graphics architecture, have been leaked in some ROCm code, discovered by Kepler_L2 on Twitter. The "performance.hpp" file references "Navi 32" with a compute unit count of 60, and the "Navi 33" with 32 compute units. We know from the "Navi 31" specifications that an RDNA3 compute unit still amounts to 64 stream processors (although with significant IPC uplifts over the RDNA2 stream processor due to dual-instruction issue-rate).
60 compute units would give the "Navi 32" silicon a stream processor count of 3,840, a 50% numerical increase over the 2,560 of its predecessor, the "Navi 22," powering graphics cards such as the Radeon RX 6750 XT. Meanwhile, the 32 CU count of the "Navi 33" amounts to 2,048 stream processors, which is numerically unchanged from that of the "Navi 23" powering the RX 6650 XT. The new RDNA3 compute unit has significant changes over RDNA2, besides the dual-issue stream processors—it gets second-generation Ray Accelerators, and two AI accelerators for matrix-multiplication.No other specs of the "Navi 32" and "Navi 33" are known at this point. If AMD is sticking with the chiplet design for the "Navi 32," it could feature a similar design to the "Navi 31," with a 5 nm GCD that has these 60 RDNA3 compute units; and either three or four 6 nm MCDs, depending on whether AMD decides to give it a 192-bit or 256-bit wide GDDR6 memory interface. It remains to be seen if the chiplet design carries on to even the smaller GPUs such as the "Navi 33." There's also no word on when AMD launches the rest of its Radeon RX 7000-series graphics card lineup. The RX 7900 series sees a December 2022 debut.
Sources:
Kepler_L2 (Twitter), HotHardware
60 compute units would give the "Navi 32" silicon a stream processor count of 3,840, a 50% numerical increase over the 2,560 of its predecessor, the "Navi 22," powering graphics cards such as the Radeon RX 6750 XT. Meanwhile, the 32 CU count of the "Navi 33" amounts to 2,048 stream processors, which is numerically unchanged from that of the "Navi 23" powering the RX 6650 XT. The new RDNA3 compute unit has significant changes over RDNA2, besides the dual-issue stream processors—it gets second-generation Ray Accelerators, and two AI accelerators for matrix-multiplication.No other specs of the "Navi 32" and "Navi 33" are known at this point. If AMD is sticking with the chiplet design for the "Navi 32," it could feature a similar design to the "Navi 31," with a 5 nm GCD that has these 60 RDNA3 compute units; and either three or four 6 nm MCDs, depending on whether AMD decides to give it a 192-bit or 256-bit wide GDDR6 memory interface. It remains to be seen if the chiplet design carries on to even the smaller GPUs such as the "Navi 33." There's also no word on when AMD launches the rest of its Radeon RX 7000-series graphics card lineup. The RX 7900 series sees a December 2022 debut.
26 Comments on AMD RDNA3 Second-largest Navi 32 and Third-largest Navi 33 Shader Counts Leaked
It feels as if the main feature of RT is "it will cut your FPS in about half, no matter what card you use"...
Now, reasons for that is that there are, actually, many (at least 5) steps to do the RT. Only one of them is "hey, RT cores, here is my goddamn structure I've spent ages preparing, can you check it for intersections?".
Preparing/maintaining that structure is done using plain old shaders.
NV's approach is also very strict on which structure is supported. AMD allows to work with any.
Epic's Lumen, which you can see here demoed on PS5 in this video, is SLOWER with "hardware RT on".
"Control" was using different codepath (NV extensions) vs Microsoft's DXR standard, had it changed recently, by the way? If not, there is no conceivable future in which AMD GPU can beat NV GPU in this games.
NV is investing in RT hard, but there had been exceptions, that people tend to ignore. AMD GPUs are notably faster in WoW RT.